To create the DHTML pop up menu you should set the following parameter:

var popupMode=1;

Then appoint code in the following format to the event you want:

return dm_popup(menuInd, pause, event, x, y)

menuInd - index of the menu on a page, >= 0.pause - sets the time when the menu will be hidden.event - constant. Do not change.x, y - optional. You should set these parameters when you want to show the menu in the specific place.
In other case the dhtml will be shown in the mouse position.